Pool Stabilizer: The Ultimate Guide


What is a pool stabilizer?

Pool stabilizers are also known as a chlorine stabilizer, a pool conditioner, or cyanuric acid, and they either come in liquid or granular forms. 

The liquid form is usually quite a bit more expensive than granular forms, although there isn’t much difference between them in terms of their effectiveness.

This chemical compound is primarily used to stabilize the chlorine in your pool water. Specifically, manufacturers combine stabilizers with chlorine because stabilizers work as sun protection for the chlorine.

As a result, the chlorine can work more effectively and last longer under strong sunlight.

Stabilizers are especially important if you live in a really hot place, such as Florida, where the sun is very strong.

Chlorine without stabilizer evaporates fast when exposed to the sunlight. As a matter of fact, It only takes a few hours for the free chlorine to almost completely evaporate without them. And this effect is only further amplified when your pool is exposed to a powerful sunlight.

But with chlorine stabilizers, your pool chlorine will last up to three to five times longer. For this reason, you will find many chlorine products that contain both chlorine and stabilizers, such as trichlor or dichlor.

Advantages of stabilized chlorine

Stabilized chlorine products come with several advantages:

For one, you don’t have to buy chlorine and a pool stabilizer separately since they come in one container.

This means you don’t have to go through the hassle of pouring them on two different occasions.

If you are pouring non-stabilized chlorine into your pool, you’ll also have to add the stabilizer to amplify its effectiveness.

With stabilized chlorine, you are eliminating that one extra step to make your life easier.

Moreover, it saves time since you don’t have to waste your time trying to figure out how much of different chemicals you need to add to your pool. 

Also, stabilized chlorine saves you money by withstanding sunlight better and lasting longer.

Drawbacks of chlorine stabilizers

But as with anything in life, if there’s positive, then there’s also negative.

Although stabilized chlorine lasts longer, it also tends to be slightly less effective.

It usually takes a little longer than unstabilized chlorine to sanitize.

This can result in stains and cloudy water in your pool.

Also, too much stabilizers can cause a lower pH in your pool, so you may end up having to spend money on buying a pH increaser to restore balance.

Furthermore, If your pool stabilizer level gets out of hand, there’s no chemical you can use to lower the level.

This means you’ll have to completely drain the pool water and refill it, which costs money and is time-consuming.

Despite its potential drawbacks, it is a necessary chemical to maintain the health of your pool.

You just need to make sure to test your pool and make needed adjustments consistently.

How much pool stabilizer to use?

If you look up online, there is a wide range of recommendations regarding the ideal range of stabilizers for your pool.

I personally recommend you maintain the level of 30 to 50 parts per million to prevent any issues with stabilizers. Try not to go past the upper end of that range. Otherwise, you increase the chance of your pool suffering from bacterial and algae growth due to poor sanitization.

You also want to keep your free chlorine level at around 7.5% of the pool stabilizer level.

In other words, if your pool has a stabilizer concentration of 40 ppm, you want your free chlorine level to be about 3 ppm (40 ppm x 0.075). The balanced ratio will help chlorine work at full capacity.

You can measure chemical levels in your pool quite easily these days since most test strips in the market come with readings for chlorine stabilizer, pH, alkalinity, and chlorine.

When to use chlorine stabilizer

As previously mentioned, there’s really no good way to get rid of pool stabilizers apart from changing the water. While this can certainly be a potential drawback, it also has its advantage.

For instance, you don’t have to constantly replenish your pool with the chlorine stabilizer since it doesn’t get used up by other chemicals or sunlight.

You can typically add a pool stabilizer at the beginning of the summer season when you open your pool. Follow the guideline for opening a pool and make sure all chemicals are added in adequate amounts for balanced pH and alkalinity.

Once that is done, you can add the pool stabilizer. Make sure to read the label well to determine how much quantity your pool needs. Also, refer to the section below so you avoid costly mistakes that can harm your pool.

Afterward, each time you pour stabilized chlorine into your pool, you are increasing the level of stabilizer by a little, and there’s usually no reason to add any more than that.

Just make sure to carefully observe your pool chemical level on a weekly basis.

In case the stabilizer level starts to go above the ideal threshold, you may consider using chlorine that doesn’t contain a stabilizer.

When should you not use a chlorine stabilizer?

If you have an indoor pool, there’s no reason to use a stabilizer since your pool is not exposed to the sunlight. It will just be an extra unnecessary chemical that serves no purpose.

When it comes to outdoor pools, the only two times when it makes sense not to keep up with your pool stabilizer level is if there’s already enough of it in your pool or if your pool requires hyper-chlorination from parasites.

Apart from that, you do not want to let the stabilizer level dip too low. 

How to add pool stabilizer

You’ll see different opinions regarding how best to add stabilizer into your pool water.

Some people advise to just pour them directly into a skimmer or your pool. Some say you should just add them into the filter.

But there’s a better way to go about it than either of those two options. In general, it’s best to pre-mix stabilizers with your pool water inside a bucket. 

This is the safest way to add stabilizers into your pool since they are acids, which means they can damage your pool and its surroundings. 

You don’t want to pour the acidic solution directly into the filter or skimmer. You want to make sure to dilute it beforehand. This will ensure the safety of your pool equipment.

Hyperchlorination with pool stabilizer

There’s a parasite called Cryptosporidium, also known as Crypto, that is formed from fecal matter, and it is very resistant to chlorine.

In other words, this parasite has the ability to rapidly infect humans even if your pool has a sufficient level of chlorine.

In such a case, it may be necessary to hyperchlorinate your pool.

And in a severe case, you may need to hyperchlorinate on a weekly basis until your pool condition improves.

If you own a small pool, it may be more time-efficient to drain the pool water, refill it, and clean all the surfaces that came in contact with the pool water.

5 Steps to hyperchlorinate your pool with chlorine stabilizer

These are the steps you can follow to successfully hyperchlorinate with chlorine stabilizers in your pool:

1) Make sure no one is in the pool while you hyperchlorinate.

2) Use chemical compounds, such as sodium hypochlorite, to increase the free chlorine level of your pool while maintaining a pH range of 7.4 to 7.6.

3) If your chlorine stabilizer level is higher than 15 ppm, bring the level down by draining some of your pool water and filling up your pool with fresh water.

This may seem counterintuitive since it’s a much lower level than the recommended level of 30 to 50 ppm.

But as we’ve mentioned earlier, stabilizers also slow down the rate at which chlorine sanitizes slightly, which is not what you want when you’re trying to hyperchlorinate your pool.

If you’ve lowered your stabilizer level below 15 ppm, follow the recommendation from the CDC’s recommendation on how much free chlorine you should add.

4) Keep the filtration system running throughout the process to disperse chlorine more quickly.

5) Backwash the filter, and you can return to swimming once you confirm all the chemical levels in your pool are balanced.


Pool stabilizers are essential for prolonging the life of chlorine under the sun. Without them, the chlorine in your pool just won’t last long enough to do its job effectively.

Luckily, chemicals such as stabilized chlorine allow you to maintain a good balance of chlorine and stabilizer so that you can sanitize your pool without too much hassle. 

That said, too much chlorine stabilizer in your pool will actually hinder the chlorine’s ability to work effectively.

In case the stabilizer level reaches a point of no return, you’ll end up having to spend a good amount of money refilling your pool with fresh water.

So, you do want to be careful not to overdose your pool with stabilizers.

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